In the movies, aliens have come to America for war (Independence Day) and friendship (E.T.). In District 9, they come to South Africa for slum living.

Twenty-eight years ago, an enormous alien ship docked in the sky above Johannesburg. Initially confounded, local armed forces were eventually able to break into the spacecraft and transfer its weakened occupants to the ground. Since then, the many tall, gangly extraterrestrials have lived in a designated area, the eponymous District 9. This soon turned into an unpleasant militarized ghetto, in which the hungry, hostile foreigners are looked down upon by citizens and dubbed "prawns."

All of this information is relayed in documentary-style video, as government agency MNU (Multi-National United) prepares to move all aliens outside the city limits. Assigned with overseeing this relocation project is nerdy worker Wikus van de Merwe (Sharlto Copley), boss' son-in-law and our human protagonist.

With the illusion of due process, Wikus and his fellow agents hand out eviction notices in scenes that play out like "COPS" with alien suspects. Although the alien race speaks in a language quite different from English, the communication is two-way. But that is about the extent of understanding. The "prawns" are not happy with their prescribed fate, and the South Africans do not care.

A critical part of MNU's mission lies in the discovery and confiscation of the aliens' highly advanced weaponry, which tests have revealed to be operated exclusively by the aliens' biology. In carrying out this task, Wikus gets sprayed with an unknown liquid substance. It instantly makes him sick and worse, giving him nosebleeds and causing fingernails and teeth to fall out. In being treated, Wikus' condition and the significance of it become clear. Suddenly, the formerly unextraordinary man is undergoing tests and being deemed an invaluable resource.

He's also wanted dead, a fact that renders him a fierce, foul-mouthed fugitive while physical changes make him more potent than ever before.

District 9 is one of those rare movies that comes from an unexpected place and gets noticed and celebrated around the world. It marks the feature directorial debut of Neill Blomkamp, a young Johannesburg-born, Vancouver-based filmmaker who arrives here from TV effects animation and commercials. Adapting from his 2005 short Alive in Joburg, Blomkamp wrote the film with Canadian novice Terri Tatchell. Their fascinating screenplay has received two major film award nominations this week alone.

This film is a refreshing anomaly. It delivers all the exciting action you could want with expert pacing and presentation. These visceral thrills are substantially aided by an intelligent story requiring little imagination to be read as an allegory for South Africa's apartheid segregation saga. You needn't fear getting a history lesson; the parallel simply adds an unacknowledged layer of sophistication to the spirited proceedings.

The depiction of extraterrestrials in this context is an immensely interesting one. As I alluded to in my introduction, aliens have typically been portrayed on film as warriors, pests, or pals. Here, they are a bullied and impoverished class, anthropomorphic enough but with decidedly animalistic qualities (they eagerly devour the cans of cat food they're tossed). Particularly compelling is the alien who rises to co-lead; single father Christopher Johnson shows more compassion and humanity than anyone else here. That said, the digital character can't upstage Wikus, who's established as an hilarious anti-hero before believably transforming into a more conventional defensive action badass.

What elevates District 9 from good to great is the technique. The film was made for a reported $30 million, a modest amount for an effects-heavy sci-fi action flick. That is to the movie's benefit. There are no gratuitous set pieces or inessential diversions. And yet, the film could show off its visual inventions because they're lively, complex, and believable, far more so than that budget would suggest. Dwelling on spectacle is something that hinders nearly all modern films to some degree. It's especially impressive that this production avoids that shortcoming while working in a universe where temptation to do such a thing should run high.

It's not your typical South African sci-fi movie that makes a big splash at the US box office, but District 9 did just that with producer Peter Jackson as its only marketable name. The film's $116 million North American gross impresses not only in its returns-to-investment multiplier but also when viewed alongside the year's comparable hits (Terminator Salvation, G-Force, Inglourious Basterds, Cloudy With a Chance of Meatballs) that were vastly easier sells.

With the movie still making news as industry award nominations roll out, Sony brings District 9 to Blu-ray and, in single and two-disc versions, DVD just three days before Christmas. We take a look at the 2-Disc Edition below.

District 9 appears in its 1.85:1 widescreen theatrical ratio. Some of the documentary and surveillance video employed clearly doesn't have the resolution and detail of film. But such is the deliberate design and for the most part, the movie looks wonderful, demonstrating how powerful and appealing a lower-budgeted production can still look when done right.

The Dolby 5.1 soundtrack makes for a very active experience, with many tactful atmospheric effects and even volume levels. There's reason that District 9 is expected to compete for the two sound Academy Awards (among other technical honors) and this winning mix makes it clear. The dialogue of the aliens, the heavily-accented, and the Nigerian gangsters who share the slums are effectively translated by player-generated yellow subtitles.

BONUS FEATURES, MENUS and PACKAGING

Three Disc 1 bonus features are included on both DVD editions of District 9.

First up is an audio commentary by director/co-writer Neill Blomkamp. In case the film didn't already make it evident, this commentary reveals Blomkamp to be smart and passionate. He talks up to the start of the end credits with almost no breaks.

Blomkamp always keeps his remarks relevant to what's on screen and provides nice insight into both his filmmaking and storytelling methods. The track isn't brilliant enough to keep you glued unless you're really interested in learning about the film's techniques, but this is definitely a bit better than your average commentary.

Next comes an unusually valuable collection of 22 deleted scenes (running 23 minutes and 27 seconds with "Play All"). Seen here: additional house calls made by Wikus and another MNU agent (in which motion-capture-suited actor Jason Cope stands in for the aliens), more of the colorful local folk and their practices, a couple bits of expert commentary, a short MNU educational video on the aliens' anatomy, an extended version of Wikus at work that feels just like the British version of "The Office", and a scene of Wikus seeking treatment from an ill-equipped clinic. The material here is quite good and hindered only by two minor nuisances: two scenes' Nigerian dialogue is not translated and copyright notices appear excessively after each excision.

The single-disc extras conclude with "The Alien Agenda: A Filmmaker's Log" (34:18), an all-purpose documentary composed of three parts. "Chapter 1: Envisioning District 9" covers the project's ideas and origins (being made after an adaptation of the video game Halo got shelved). Running as long as the other two parts put together, "Chapter 2: Shooting District 9" looks at production, specifically the varying visual techniques, on-set challenges, and art direction. "Chapter 3: Refining District 9" wraps up with an overview of post-production work (editing and sound design) and some final thoughts. Overall, most viewers will find this a sufficient and well-produced making-of piece.

Disc One opens with previews for Moon, 2012, Legion, Michael Jackson's: This Is It, and Universal Soldier: Regeneration. The disc's Previews menu holds these and additional promos for The Boondock Saints II; All Saints Day, Blu-ray, Zombieland, Black Dynamite, Hardwired, The Stepfather, Blood: The Last Vampire, and "Damages": The Complete Second Season.

Those wanting more will find it on the 2-Disc Edition's second platter, which holds four exclusive topical featurettes.

"Metamorphosis: The Transformation of Wikus" (9:50) details the practical makeup and prosthetic work needed to give the film's lead different stages of alien transformation. Actor Sharlto Copley keeps his character's accent and his sense of humor while his sedentary endurance gets tested during hours of applications.

"Innovation: The Acting and Improvisation of District 9" (12:00) covers how a technique often reserved for comedies

(most commonly Judd Apatow ones) was employed here. Cast and crew sound off on the challenges and rewards of improvising.

"Conception and Design: Creating the World of District 9" (13:15) explains some of the thought that went into designing the aliens, their weaponry, eggs, and ships. MNU wares and the environments are also touched upon, as are Blomkamp's cinematic inspirations.

Finally, "Alien Generation: The Visual Effects of District 9" (10:10) delves into the "how", as in how steadily-moving Cope, on stilts and in motion capture pajamas, was painted out and digitally replaced by animated creatures. It does more telling than showing, but at least it doesn't get too technical or dry.

Disc Two loads with trailers for Dear John, Dark Country, and Takers. Its Previews menu adds promos for The Damned United, "Rescue Me": Season 5, "The Shield", and By the People: The Election of Barack Obama.

A handful of bonus features are exclusive to District 9's Blu-ray edition: an interactive map of the film's Johannesburg, a digital copy of the film (which there's plenty of room for on the second DVD), and BD-Live extras Cinechat and movieIQ.

On your first visit, Disc 1 lets you choose between human and alien versions of the animated main menu. Most of the selection screens are silent and static, including all of Disc 2's few pages. The 2-Disc Edition includes a snazzy embossed slipcover. Nothing but the discs are found inside the standard-sized keepcase.

CLOSING THOUGHTS

District 9 dishes out its interesting aliens-in-Johannesburg premise immediately and matter-of-factly. It then proceeds to move us deftly and unconventionally through a gripping tale, whose comments upon human nature and xenophobia can easily be pondered or ignored.

The execution is close to flawless, the effects dazzling, the action riveting, and the presentation highly compelling. This stands as one of the best films of the year and this soon-concluded decade. Not everyone will appreciate it (I've read the non-gratuitous, unrealistic gore has turned some off), but they should. This is superb, accessible, thoughtful science fiction.

I'm obviously recommending District 9 as a movie worth picking up. If you've adopted Blu-ray, there is just one version to get. If you're still happy with DVD, you've got to make the now-standard choice between one and two-disc versions. While the bonus features are of a refreshingly high quality, the single-disc edition holds onto the best of the bunch in a commentary, general documentary, and rich bounty of deleted scenes. Based on release date prices, you'd be paying $7 more for a cardboard sleeve and 45 additional minutes of featurettes and that gap will only widen as time passes. You can't go wrong either way, but you'd have to be a pretty serious extras/slipcover junkie to opt for the premium version.